P2P tends not to work very well, and is going on (and mainly failing) in a few different places.  Coinjoin is a red flag for the feds, so devs dont really want to risk it.  Maybe some will, tho.  Fees wont add up to much I expect, and mixing can be done in many other places.  I think AI integration will be a good match for nostr.  Combine that with games too.  Lots of viral paths for social games.